Photographic products, processes and processing compositions containing a glucoside of a phenolic hydroxyl compound



United States Patent 3,287,126 PHOTOGRAPHIC PRODUCTS, PROCESSES AND PROCESSING COR/ POSITIONS CONTAINING A GLUCOSIDE OF A PHENOLIC HYDROXYL COMPOUND 1 Howard G. Rogers, Weston, Mass., assignor to Polaroid Corporation, Cambridge, Mass., a corporation of Delaware No Drawing. Filed Dec. 28, 1962, Ser. No. 247,864 13 Claims. (CI. 96-49) This invention relates to photography and more particularly to products, compositions and processes for providing color diffusion transfer. images having enhanced stability to sunlight.

One object of this invention is to provide color diffusion transfer images having enhanced stability to sunlight.

Another object is to provide novel products and processes employing compositions for the development of silver halide emulsions which compositions contain a glucoside of a phenolic hydroxyl compound.

Other objects of the invention will in part be obvious and will in part appear hereinafter.

The invention accordingly comprises the processes involving the several steps and the relation and order of one or more such steps with respect to each of the others, and the products and compositions possessing the features, properties and the relation of elements which are exemplified in the following detailed disclosure, and the scope of the application of which will be indicated in the claims.

For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description.

US. Patent No. 2,983,696, issued May 9, 196-l,-to' Howard G. Rogers, discloses processes employing dye developers to form color transfer images and products useful therein. The copending application of Edwin H. Land and Howard G. Rogers, Serial No. 565,135, filed February 13, 1956, discloses the use of such dye developers in integral multilayer negatives to give multicolor transfer images.

The above-mentioned US. Patent No. 2,983,606 discloses and claims a highly useful method of forming color images by diffusion transfer wherein the color-providing substances are dye developers. As set forth therein, a dye developed is a compound which is both a dye and a sliver halide developing agent. Particularlyuseful and preferred dye developers are azo and anthraquinone dyes which contain one or more hydroquinonyl groups. The silver halide developing group preferably is linked to the 3,287,126 Ce Patented Nov. 22, 1966 duction of the pH by providing an acid-reacting layer,

preferably a polymeric acid such as a partial ester of poly-(ethylene/maleic anhydride), adjacent to the image layer, whereby the alkali ions are caused to diffuse to said acid-reacting layer and are there trapped or precipitated.

The acid polymer layer contains at least sufiicient acid groups to effect a reduction in the pH of about 13 to 14 to a pH of about 5 to 8 within a short time after imbibition. The pH of the processing combination preferably is of the order of at least 13 to 14.

The copending application of Samuel Dershowitz, Serial No. 247,868, filed December 28, 1962, provides dye developer color images having increased stability to light by associating a glucoside of a phenolic hydroxyl with said image.

It has now been found that a greater degree of stability to light can be achieved in a color image formed by the dye developer diffusion transfer process on an imagereceiving element containing a layer of a polymeric acid by including a glucoside of a phenolic hydroxyl compound in the liquid processing composition used in the formation of said color image.

In carrying out the preferred method of this invention, the photosensitive element containing a silver halide emulsion is exposed and wetted with a liquid processing composition and the photosensitive element superposed, prior to, during, or after said wetting, on the image-receiving element. As the exposed silver halide emulsion is devel oped, an imagewise distribution of diffusib'le, unoxidized dye developer formed as a function of development, and at least a portion of said imagewise distribution, is transferred by imbibition to the superposed image-receiving element. The glucoside of a phenolic hydroxyl contained in the processing composition contacts the image-receiving stratum and a substantial portion of said glucoside is deposited thereon; thereby providing enhanced light stability to the color image formed by the dye developer transferred to the image-receiving element. After completion of the imbibition period, the positive image may i be viewed by stripping the image-receiving element from of a particularly useful compound is arbutin. Numerous chromophoric system of the dye developer through a '5 suitable group of atoms which are effective to interrupt any system of conjugation and resonance between the silver halide developing group, e.g., a hydroquinonyl radical, and the chromophoric systemor dye portion of the molecule. Such insulatinglin'kages have been found to be quite effective in avoiding or essentially eliminating any significant change in'the color characteristics of the dye developer should the hydroquinonyl group be oxidized-to the quinone, e.g., by aerial oxidation of the dye developers'in the separated image-receiving layer.

The copending application of Edwin H. Land, Serial No; 234,864,filed November "1, 1962, discloses and claims the invention which comprisesadjusting the alkalinity or pH of the environmentof the transferred dye developer on the image-receiving layer, prior to exposing the surface of the image-receiving layer to air, to a level at least substantially precluding alkaline oxidation of the developing radical. As a result of such pH adjustment, a remarkable improvement in the stability to light of the thus-formed color images is noted. The above-mentioned application of Edwin H. Land, Serial No. 234,864, provides for reexamples of other such compounds suitable for use Within the scope of this invention are set forth in the above-noted application of Samuel Dershowitz, Serial No. 247,868.

Concentrations of the glucoside of a phenolic hydroxyl which have been found to be useful in accordance with this invention fall within the range of 0.1 to 10%. In a preferred embodiment, arbutin is used at levels of about 0.5 to 5% The amount of the glucoside of a phenolic hydroxyl compound used will vary, with many factors such, for example, as the original color fastness of'the dye developers, the amount of sunlight the colored image will be exposed to during its life expectancy, the solubility of the glucosides, yellowing of the color image, etc. The amount of stabilizer employed to provide protection may be referred to as an effective amount, i.e., an amount effective to give the desired protection, and it will be understood that such an amount will vary with many factors, such as mentioned above, and can be readily deterboxymethyl cellulose.

3 hydroxide or potassium hydroxide, a dye developer and, in some instances, it may contain an additional silver halide developing agent. .If the liquid processing composition is to be applied to the emulsion by being spread thereon, preferably in a relatively thin, uniform layer, it may also include a viscosity-increasing compound constituting film-forming material of the type which, when spread overa water-absorbent base, will form a relatively firm and relatively stable film. A preferred film-forming material is a high molecular weight polymer such as a polymeric, water-soluble ether inert to an alkali solution, as, for example, a hydroxyethyl cellulose or sodium carthickening agents whose ability to increase viscosity is substantially unaifected when left in solution for a long period of time may also be used.

Liquid processing compositions suitable for use in this invention which contain cesium hydroxide are disclosed and claimed in the copending application of George H. Fernald, Jr., Serial No. 247,867, filed December 28, 1962, and compositions containing potassium hydroxide are disclosed and claimed in the copending application of Dorothy C. Mendelsohn, Serial No. 247,863, filed December 28, 1962.

The liquid processing composition may also contain ant-ifog-gants, e.-g., benzotriazole, and quaternary ammonium compounds, e.g., N phenethyl-a-picolinium bromide, N-benzyl-a-picolinium bromide, as disclosed in the copending application of Milton Green and Howard G. Rogers, Serial No. 50,851, filed August 22, 1960, now -U.S. Patent 3,173,786.

The novel processing compositions of this invention were tested in diffusion transfer processes on multilayer photosensitive elements prepared in the manner similar to that disclosed in the above-mentioned US. Patent No. 2,983,606 and in the above-mentioned copending application of Edwin H. Land, and Howard G. Rogers, Serial No. 565,135, filed February 13, 1956, using image-receiving elements prepared in accordance with the invention disclosed and claimed in the above-mentioned copending application of Edwin H. Land, Serial No. 234,864, filed November 1, 1962.

In the examples set forth below, reference to a multicolor negative is to a multilayer negative in which the blue-sensitive, green-sensitive, and red-sensitive silver iodobromide emulsion layers have positioned behind them, respectively, a yellow dye developer, a magenta dye developer, and a cyan dye developer. A gelatin interlayer is positioned between the yellow dye developer layer and the green-sensitive emulsion, and between the magenta dye developer and the red-sensitive emulsion.

Cyan

' on no 0 maven-0H l H l l H on 1LH-C H-CH in,

1,4-bls-[a-methyl-B-hydroquinonyl-ethylamino]- 5,S-Gihydroxy-anthraqumone Roi Other film-forming materials or 4 Magenta 0H 0H 011,-0 HN=N isopropoxy-l-naph Yellow The following processing compositions are given to illustrate the present invention and are not intended to be limiting.

Processing composition No. 1 (control).

Water cc 100.00 NaOH gm 5.17 Hydroxyethyl cellulose (high viscosity) [commercially available from Hercules Powder Co., Wilmington 99, Delaware, under the trade name An image-receiving element was prepared by coating a sub-coated baryta paper with a layer of partial butyl half ester of poly-(ethylene/maleic anhydride) approximately Y 0.8 mil thick, followed by a layer of polyvinyl alcohol approximately 0.4 mil thick. Over this was applied a 2: 1 mixture, by weight, of polyvinyl alcohol and poly-44 vinyl-pyridine to provide an image-receiving layer ,ap-

proximately 0.40 mil thick.

The effectiveness of the novel processing compositions.

of this invention in providing protection to color images was measured by exposing a multilayer, multicolor negative as described above, and spreading a thin layer of processing composition between the above-mentioned image-receiving element and said exposed multicolor negative as they were brought intosuperposedrelationship.

After an imbibition period of 1 /2 minutes, the image-receiving element was separated from the negative. The

image-receiving element, now containing a color transfer image thereon, was subjected to an accelerated fading test.

The positive color prints under test were mounted under glass and positioned three inches from the glass, the glass being positioned at an angle of 45 to the horizontal and facing south. In this manner, the prints were exposed on the Florida seacoast on a 24 hour basis for the period necessary to record the desired number of gram-calories per square centimeter -(Langleys) of solar radiation, as recorded from sunrise to sunset using an Epply Pyrheliometer [made by the Epply Laboratory, Inc., Newport, R.I.] as the sensing unit. An evaluation of the eifectiveness of the novel processing compositions of this invention was then made by comparing the degree of magenta fading of a control sample (Processing Composition No. 1) with those prepared using processing compositions containing a glucoside of a phenolic hydroxyl, the transfer images being formed on image receiving elements prepared as described above.

The results, set forth below in tabular form, show the percent of magenta fading after exposure to 350, 700 and 1400 Langleys.

Percent Magenta Fading Solar Radiation in Langleys -r 350 700 1,400

Processing Composition No. 1 (Control) 7 16 42 Processing Composition No. 2 2 13 34 Processing Composition No. 3 O 4 21 In a preferred embodiment, the processing composition includes an ultraviolet light absorber in addition to the glucoside of a phenolic hydroxyl compound. Use of ultraviolet light absorbers in the processing composition is disclosed and claimed in my copending application, Serial No. 247,866, filed December 28, 1962, as a continuationin-part of my copending application, Serial No. 786,766, filed January 14, 1959, now abandoned. An example of a processing composition containing an ultraviolet light absorber and a glucoside of a phenolic hydroxyl compound is:

Processing Composition N0. 4

Accelerating fading tests of multicolor images using processing composition No. 4 with the above-described polymeric acid layer-type receiving sheet showed 16% magenta fading after 700 Langleys and 17% magenta fading after 1400 Langleys.

It can be readily seen that the present invention provides color images of increased stability to light.

It should be noted that the above-described accelerated fading test is a rather severe method of examination which is utilized to rapidly evaluate the effect on image stability to light of the various processing compositions.

The glucoside of a phenolic hydroxyl may be supplied to the processing composition during processing as well as being disposed therein prior to processing. For example, the glucoside compound may be located in a separate polymeric layer in the photosensitive layer and be solubilized therefrom during processing by the processing solution and transferred to the image-receiving element along with the dye developers.

Since certain changes may be made in the above products, compositions and processes without departing from the scope of the invention herein involved, it is intended that all matter contained in the above description shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. The process of forming color images by diffusion transfer, comprising the steps of applying an alkaline processing composition to an exposed photosensitive element, said processing composition containing a glucoside of a phenolic hydroxyl compound, forming an imagewise distribution of dilfusible dye developer in said photosensitive element as a function Olf said development, transfering to a superposed image-receiving layer a quantity of said difiusible dye developer sufiicient to form a visible color image thereon, reducing the pH of said image-receiving layer after said transfer has been effected from a pH in excess of 12 to a pH below about 11, and thereafter separating said image-receiving layer from said supenposed relationship.

2. The process as defined in claim 1 wherein said pH reduction is efiected by diffusion of alkali ions from said image-receiving layer to an adjacent layer containing a polymer containing acid groups.

3. The process as defined in claim 1 wherein said glucoside of a phenolic hydroxyl compound is arbutin.

4. The process as defined in claim 3 wherein said arbutin is present in said processing composition at a level of about 0.5 to 5%.

5. A photographic product for a color diffusion transfer process comprising a photosensitive element, including at least one silver halide emulsion having associated therewith a dye developer, each said dye developer being adapted to form an irnagewise distribution of mobile dye developer as a function of development of the associated silver halide emulsion, an image-receiving element, and a rupturable container holding an aqueous alkaline processing solution, said aqueous alkaline processing solution comprising a glucoside of a phenolic hydroxyl compound, said elements being capable of being superposed, and said container being associated with said elements in such :a manner that the container, upon being ruptured, is capable of releasing said processing composition for spreading therebetween, said image-receiving element comprising, in sequence, a support, a layer containing a polymeric acid coated on said support, and an image-receiving layer, said image-receiving layer being adapted to provide a visible dye image upon transfer to said layer of said dye developer.

6. A product as defined in claim 5 wherein said photosensitive element contains cyan, magenta and yellow dye developers.

7. A product as defined in claim 5 wherein said glucoside of a phenolic hydroxyl compound is arbutin.

8. A product as defined in claim 7 wherein said arbutin is present in said processing composition at a level of about 0.5 to 5%.

9. A product as defined in claim 5 wherein said polymeric acid is a partial ester of poly-(ethylene/ma-leic anhydride).

10. A process which comprises the steps of permeating an exposed photosensitive element, including a silver halide emulsion, with an alkaline liquid processing composition, providing said composition with a glucoside of a phenolic hydroxyl compound, developing said exposed emulsion and thereby forming an imagewise distribution of an unoxidized dye developer, and transferring at least a portion of said glucoside of a phenolic hydroxyl compound and of said unoxidized dye developer to a superposed image-receiving element, said image-receiving element comprising, in sequence, a support, a layer containing a polymeric acid coated on said support, and an image-receiving layer, said image-receiving layer being adapted to provide a visible dye image upon transfer to said layer of said dye developer.

11. The process as defined in claim 10 wherein said "glilcoside of a phenolic 'hydroxyl compound is arbutin.

13. The process as defined in claim 10 wherein said i polymeric acid is a partial ester of poly- (ethylene/maleic anhydride).

No references cited.

5 NORMAN G. TORCHIN, Primary Examiner.

J. T. BROWN, Assistant Examiner. 

1. THE PROCESS OF FORMING COLOR IMAGES BY DIFFUSION TRANSFER, COMPRISING THE STEPS OF APPLYING AN ALKALINE PROCESSING COMPOSITION TO AN EXPOSED PHOTOSENSITIVE ELEMENT, SAID PROCESSING COMPOSITION CONTAINING A GLUCOSIDE OF A PHENOLIC HYDROXYL COMPOUND, FORMING AN IMAGEWISE DISTRIBUTION OF DIFFUSIBLE DYE DEVELOPER IN SAID PHOTOSENSITIVE ELEMENT AS A FUNCTION OF SAID DEVELOPMENT, TRANFERING TO A SUPERPOSED IMAGE-RECEIVING LAYER A QUANTITY OF SAID DIFFUSIBLE DYE DEVELOPER SUFFICIENT TO FORM A VISIBLE COLOR IMAGE THEREON, REDUCING THE PH OF SAID IMAGE-RECEIVING LAYER AFTER SAID TRANSFER HAS BEEN EFFECTED FROM A PH IN EXCESS OF 12 TO A PH BELOW ABOUT 11, AND THEREAFTER SEPARATING SAID IMAGE-RECEIVING LAYER FROM SAID SUPERPOSED RELATIONSHIP. 